Try to turn the compressor by hand. It should be possible to turn it around. It should turn around smoothly, without any 'hickups' (be sure to completely shut down the air compressor!). Check the isolation of the motor windings.
[pdf] Integrated design saves space, reduces installation, and boosts overall efficiency. High efficiency and lower energy use with two-stage compression for heavy-duty demand. Optimized for processes needing large airflow at low pressure, cutting energy waste.
[pdf] Atlas Copco, Stockholm, Sweden, unveiled its latest generation of clean compressors at bauma 2019 — new sustainable mobile air equipment powered by lithium-ion batteries and energy-efficient electric motors.
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